We report two cases of skeletal fluorosis in two men, 55 and 69 year-old. The physical findings and the roentgenograms were typical and chemical analysis confirmed the diagnosis. Surprisingly, fluoride concentrations in blood and urine were increased at the beginning of the hospitalizations and lower during the hospitalizations. The origin of fluor intake remained unknown, leading to consider a possible criminal poisoning. Then, we discuss the attitude of physician in a case a possible criminal poisoning: denunce the crime to the police or not, as regards french law.